aboutsummaryrefslogtreecommitdiff
path: root/gcc/ada/5hparame.ads
blob: ea71f8fa5a1bb44e00868f9a988df7e69fe63efe (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
------------------------------------------------------------------------------
--                                                                          --
--                         GNAT COMPILER COMPONENTS                         --
--                                                                          --
--                    S Y S T E M . P A R A M E T E R S                     --
--                                                                          --
--                                 S p e c                                  --
--                                                                          --
--                            $Revision: 1.1 $
--                                                                          --
--          Copyright (C) 1992-2000 Free Software Foundation, Inc.          --
--                                                                          --
-- GNAT is free software;  you can  redistribute it  and/or modify it under --
-- terms of the  GNU General Public License as published  by the Free Soft- --
-- ware  Foundation;  either version 2,  or (at your option) any later ver- --
-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
-- for  more details.  You should have  received  a copy of the GNU General --
-- Public License  distributed with GNAT;  see file COPYING.  If not, write --
-- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
-- MA 02111-1307, USA.                                                      --
--                                                                          --
-- As a special exception,  if other files  instantiate  generics from this --
-- unit, or you link  this unit with other files  to produce an executable, --
-- this  unit  does not  by itself cause  the resulting  executable  to  be --
-- covered  by the  GNU  General  Public  License.  This exception does not --
-- however invalidate  any other reasons why  the executable file  might be --
-- covered by the  GNU Public License.                                      --
--                                                                          --
-- GNAT was originally developed  by the GNAT team at  New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc.      --
--                                                                          --
------------------------------------------------------------------------------

--  This is the HP version of this package

--  This package defines some system dependent parameters for GNAT. These
--  are values that are referenced by the runtime library and are therefore
--  relevant to the target machine.

--  The parameters whose value is defined in the spec are not generally
--  expected to be changed. If they are changed, it will be necessary to
--  recompile the run-time library.

--  The parameters which are defined by functions can be changed by modifying
--  the body of System.Parameters in file s-parame.adb. A change to this body
--  requires only rebinding and relinking of the application.

--  Note: do not introduce any pragma Inline statements into this unit, since
--  otherwise the relinking and rebinding capability would be deactivated.

package System.Parameters is
pragma Pure (Parameters);

   ---------------------------------------
   -- Task And Stack Allocation Control --
   ---------------------------------------

   type Task_Storage_Size is new Integer;
   --  Type used in tasking units for task storage size

   type Size_Type is new Task_Storage_Size;
   --  Type used to provide task storage size to runtime

   Unspecified_Size : constant Size_Type := Size_Type'First;
   --  Value used to indicate that no size type is set

   subtype Ratio is Size_Type range -1 .. 100;
   Dynamic : constant Size_Type := -1;
   --  The secondary stack ratio is a constant between 0 and 100 which
   --  determines the percentage of the allocated task stack that is
   --  used by the secondary stack (the rest being the primary stack).
   --  The special value of minus one indicates that the secondary
   --  stack is to be allocated from the heap instead.

   Sec_Stack_Ratio : constant Ratio := Dynamic;
   --  This constant defines the handling of the secondary stack

   Sec_Stack_Dynamic : constant Boolean := Sec_Stack_Ratio = Dynamic;
   --  Convenient Boolean for testing for dynamic secondary stack

   function Default_Stack_Size return Size_Type;
   --  Default task stack size used if none is specified

   function Minimum_Stack_Size return Size_Type;
   --  Minimum task stack size permitted

   function Adjust_Storage_Size (Size : Size_Type) return Size_Type;
   --  Given the storage size stored in the TCB, return the Storage_Size
   --  value required by the RM for the Storage_Size attribute. The
   --  required adjustment is as follows:
   --
   --    when Size = Unspecified_Size, return Default_Stack_Size
   --    when Size < Minimum_Stack_Size, return Minimum_Stack_Size
   --    otherwise return given Size

   Stack_Grows_Down  : constant Boolean := False;
   --  This constant indicates whether the stack grows up (False) or
   --  down (True) in memory as functions are called. It is used for
   --  proper implementation of the stack overflow check.

   ----------------------------------------------
   -- Characteristics of types in Interfaces.C --
   ----------------------------------------------

   long_bits : constant := Long_Integer'Size;
   --  Number of bits in type long and unsigned_long. The normal convention
   --  is that this is the same as type Long_Integer, but this is not true
   --  of all targets. For example, in OpenVMS long /= Long_Integer.

   ----------------------------------------------
   -- Behavior of Pragma Finalize_Storage_Only --
   ----------------------------------------------

   --  Garbage_Collected is a Boolean constant whose value indicates the
   --  effect of the pragma Finalize_Storage_Entry on a controlled type.

   --    Garbage_Collected = False

   --      The system releases all storage on program termination only,
   --      but not other garbage collection occurs, so finalization calls
   --      are ommitted only for outer level onjects can be omitted if
   --      pragma Finalize_Storage_Only is used.

   --    Garbage_Collected = True

   --      The system provides full garbage collection, so it is never
   --      necessary to release storage for controlled objects for which
   --      a pragma Finalize_Storage_Only is used.

   Garbage_Collected : constant Boolean := False;
   --  The storage mode for this system (release on program exit)

end System.Parameters;